Thanks guys. Yes, it's a daytime FARS unit. It was recently refurbished by Davis at a cost of $200. So I'm not exactly happy but I'm sure it's been enough months now that they won't cover it. Does swapping out these fan motors require any soldering or electrical knowledge? It is completely plug and play, other than centering the motor?

Thanks guys. Yes, it's a daytime FARS unit. It was recently refurbished by Davis at a cost of $200. So I'm not exactly happy but I'm sure it's been enough months now that they won't cover it. Does swapping out these fan motors require any soldering or electrical knowledge? It is completely plug and play, other than centering the motor?

For the Jameco motor replacement, it does require some soldering skill. Also, you will need to "dig out" the motor from a bunch of hot melt glue.If you are just replacing the entire fan assembly, it is not that bad. Just keep track of the plates as you disassemble the shield. I used pencil and numbered them.

That is one of the good points about DFARS vs 24 hr. The sensor is more open so the Dfars fan can die sometimes without notice depending on sun intensity, the 24 hr is different you would notice right away it does better job aspirating around the clock but requires operational fan to draw air into sensor chamber.

Thanks guys. Yes, it's a daytime FARS unit. It was recently refurbished by Davis at a cost of $200. So I'm not exactly happy but I'm sure it's been enough months now that they won't cover it. Does swapping out these fan motors require any soldering or electrical knowledge? It is completely plug and play, other than centering the motor?

For the Jameco motor replacement, it does require some soldering skill. Also, you will need to "dig out" the motor from a bunch of hot melt glue.If you are just replacing the entire fan assembly, it is not that bad. Just keep track of the plates as you disassemble the shield. I used pencil and numbered them.

Greg H.

Curious as to why you would need to number the plates? Obviously the bottom and top plates are physically different, but most plates in the middle are the same?

Somewhat related, can anyone tell me the specific p/n or description for the connector on the solar panel lead? Buying components to go stand-alone and based on the tiny solar panels, I've thought it would be more reliable to power from an external solar panel/battery/charge controller setup. So I'd need to either procure the connector on the solar panel leads or procure the jack on the console A/C adapter. If you can tell me both of those p/ns that would be great. Might Ryan at Scaled Instruments have these pieces?

Steven the Davis larger solar cell is more than enough to charge a set of 'C' batteries for nighttime and power the fan. They are 3v fans and run about 2.4v if memory serves. If you run at higher voltage the fan won't last long so larger panels aren't necessary. If you want a more reliable fan that really pulls some serious air (Don't go too high) some here are using AC fans. I use this AC fan. Just make sure you are on a GFCI circuit outside. It will run for years 24/7 and never fail, rated at -40C for cold climates. Remember draw air across sensor so fan heat is exhausted out top of shield and not down on sensor.

Thanks guys. Yes, it's a daytime FARS unit. It was recently refurbished by Davis at a cost of $200. So I'm not exactly happy but I'm sure it's been enough months now that they won't cover it. Does swapping out these fan motors require any soldering or electrical knowledge? It is completely plug and play, other than centering the motor?

For the Jameco motor replacement, it does require some soldering skill. Also, you will need to "dig out" the motor from a bunch of hot melt glue.If you are just replacing the entire fan assembly, it is not that bad. Just keep track of the plates as you disassemble the shield. I used pencil and numbered them.

Greg H.

Curious as to why you would need to number the plates? Obviously the bottom and top plates are physically different, but most plates in the middle are the same?

I just wanted to get them in the same order. I thought that there were a couple of oddball ones in the stack if I remember correctly.

Thanks guys. Yes, it's a daytime FARS unit. It was recently refurbished by Davis at a cost of $200. So I'm not exactly happy but I'm sure it's been enough months now that they won't cover it. Does swapping out these fan motors require any soldering or electrical knowledge? It is completely plug and play, other than centering the motor?

For the Jameco motor replacement, it does require some soldering skill. Also, you will need to "dig out" the motor from a bunch of hot melt glue.If you are just replacing the entire fan assembly, it is not that bad. Just keep track of the plates as you disassemble the shield. I used pencil and numbered them.

Greg H.

Curious as to why you would need to number the plates? Obviously the bottom and top plates are physically different, but most plates in the middle are the same?

I thought that there were a couple of oddball ones in the stack if I remember correctly.Greg H.

No sir, they're all the same. However, they can be a little frustrating to line up properly.

Steven the Davis larger solar cell is more than enough to charge a set of 'C' batteries for nighttime and power the fan. They are 3v fans and run about 2.4v if memory serves. If you run at higher voltage the fan won't last long so larger panels aren't necessary. If you want a more reliable fan that really pulls some serious air (Don't go too high) some here are using AC fans. I use this AC fan. Just make sure you are on a GFCI circuit outside. It will run for years 24/7 and never fail, rated at -40C for cold climates. Remember draw air across sensor so fan heat is exhausted out top of shield and not down on sensor.

That's the fan I have, suggested by Randy. Installed on 7/10/17 and haven't looked back!

Steven the Davis larger solar cell is more than enough to charge a set of 'C' batteries for nighttime and power the fan. They are 3v fans and run about 2.4v if memory serves. If you run at higher voltage the fan won't last long so larger panels aren't necessary. If you want a more reliable fan that really pulls some serious air (Don't go too high) some here are using AC fans. I use this AC fan. Just make sure you are on a GFCI circuit outside. It will run for years 24/7 and never fail, rated at -40C for cold climates. Remember draw air across sensor so fan heat is exhausted out top of shield and not down on sensor.

No, wasn't looking to go A/C - just the opposite. Goal is self-contained setup and knew that external solar panel, 12V battery and charge controller with stepdown to fan voltage would ensure fan ran at optimum speed throughout the day rather than slowing so much with marginal sunlight hitting the 10 sq inch panel.

So no one can tell me the connectors on the solar panel lead and for the console A/C adapter? There are a couple dozen jack styles for A/C adapters.

No, wasn't looking to go A/C - just the opposite. Goal is self-contained setup and knew that external solar panel, 12V battery and charge controller with stepdown to fan voltage would ensure fan ran at optimum speed throughout the day rather than slowing so much with marginal sunlight hitting the 10 sq inch panel.

So no one can tell me the connectors on the solar panel lead and for the console A/C adapter? There are a couple dozen jack styles for A/C adapters.

The drawing on the Davis #6625 AC adapter which plugs into the ISS J11 connector (above the CR123A battery) shows the OUTSIDE metal ring is NEGATIVE(-) and the INSIDE receptacle is POSITIVE(+).

The solar panel for my spare ISS (looking down at backside) has the left wire being NEGATIVE and the right wire (with white strobe lines on insulation) being POSITIVE, which translates to J31 Solar Panel on ISS being: top pin is NEG and bottom pin (closest to CR123A battery) is POS.

Pretty easy to figure out positive/negative, but need enough information to order the connectors from Digikey or elsewhere.

Okay, so I disassembled the fan and took the old motor out and installed the new motor. Soldered the connections back just like they were before. Reinstalled everything and I've got the exact same symptoms. Fan won't run unless I give it a flip with my finger and only then will it run if the solar panel is directly facing the Sun at a 90 degree angle. I checked battery voltage and it is at 2.9 volts. What in the world is going on here? Solar panel going bad?

I checked battery voltage and it is at 2.9 volts. What in the world is going on here? Solar panel going bad?

The battery voltage has nothing to do with the fan in full sun, because the solar panel itself powers the fan. When there's less than "full" sun, then the batteries start to contribute. You need to check what voltage the solar panel itself is putting out, should be around 2.4-2.5 vdc iirc, but with a full charge on the battery, makes me think it's ok. Strange....

Okay, so I disassembled the fan and took the old motor out and installed the new motor. Soldered the connections back just like they were before. Reinstalled everything and I've got the exact same symptoms. Fan won't run unless I give it a flip with my finger and only then will it run if the solar panel is directly facing the Sun at a 90 degree angle. I checked battery voltage and it is at 2.9 volts. What in the world is going on here? Solar panel going bad?

What happens if you replace the batteries (temporarily of course) with good non-rechargeable ones?

What's the output voltage of the solar panel when directly facing the sun (preferably when disconnected from the fan)?

BTW, I know this sounds like , but since you put in another motor only, are you positive the fan blades are not in any contact with the housing? These motors have nowhere near enough torque to make any kind of contact.

Yep I centered the fan perfectly using wooden shims. It's good and solid. Tomorrow when the sun is back up I will take measurements of the output voltage at the solar panel. Don't know why it skipped my mind to do that tonight. Is it possible for the solar panels to go bad like that?

Wow, I completely spaced this portion of the thread. Since this is a DFARS, you have no batteries that get charged in the first place. Sorry, but others will have to help as I have no idea what the output voltage is for DFARS.